1. Field of the Invention
The present invention belongs to a technical field of an information distribution system, a registration apparatus, an information processing apparatus, a recording medium having a registration program memorized in it, and a storage medium having an information processing program memorized in it.
2. Discussion of the Related Art
In recent years, a delivery system for carrying out so-called content delivery of accessing a server or the like, which stores the above content through a network such as internet, and of enabling to watch and listen content desired to watch and listen after delivering the content thus required to the node is actively researched and developed.
As one of the delivery system, there is a delivery system of directly and mutually sending and receiving the content among nodes belonging to the network, for example there is a delivery system of P2P (pear to pear) type, dispersing each content among a plurality of nodes and enabling the plurality of nodes to use in common. This delivery system of P2P type gets eye as a measure for solving drawbacks of conventional client-server model, i.e. concentration of access to a server and high administration cost.
Further, in this field of research concerning information delivery system of pear-to-pear type as one system of P2P type delivery system, each node does not recognizes link information to all nodes, participating in an overlay network, which is logically constructed in use of for example a distributed hash table (hereinafter referred to as distributed hash table (DHT)), but retains link information (e.g. IP address) to a part of nodes obtained in participating to the overlay network and carries out inquiry of data or the like on the basis of such the link information.
In such the overlay network, even when participation and withdrawal (disembarrassment) are frequently carried out in such the overlay network, it is necessary that dispersion of load should be properly done. Non-Patent Document 1 discloses a technique that dispersion of load is adequately done even when participation and withdrawal (disembarrassment) are frequently done. A proposal concerning production and arrangement in a conventional technique is for example described in the following Patent Document 1 and Non-Patent Document 1.
According to Patent Document 1, there is proposed a method of making and arranging a replica (reproduction) while maintaining a balance of network in its entirety inside a service group on a network with reference to overall size (overall information amount) and number of contents (replicas) existing in each of the nodes, connected inside the service group on the network.
Further, in the Patent Document 2, there is proposed a measure of dynamically making replica in response to access frequency without administrating overall information by giving a number indicative of importance to each of the contents.    Non-Patent Document 1: “Lightweight Load Balancing for Distributed Hash Tables”, THE INSTITUTE OF ELECTRONICS, INFORMATION AND COMMUNICATION ENGINEERS, TECHNICAL REPORT OF IEICE    Patent Document 1: Japanese Unexamined Patent Publication No. 2003-99337    Patent Document 2: Japanese Unexamined Patent Publication No. 2003-216521